It is most likely random. The egg color gene is probably in both hen and rooster, and the outcome would produce blue eggs or brown.
But something is telling me it would likely lay green eggs. Because the olive/greenish color is, in truth, blue with a thin layer of brown, maybe it would combine them and lay green.
However, if an ee/frizzle bred an ee, there is a 75% chance of there being blue eggs, but not including green eggs. Just hatch a lot and see what you get,